How to change font style in TabItem header?

[Charles Bates]

Hello,
VS 2010, Telerik Controls for Silverlight 2010.1.422.1030.

When a tabitem is selected, I would like its header's font to be bold.  
In the TabCntrl_SelectionChanged handler, I added this:

TextBlock tb = ti.Header as TextBlock;
if (null != tb)
{
    tb.FontWeight = FontWeights.ExtraBold;
}

I has no effect, though.
what am I doing wrong?
Thanks for any insight...

[Dimitrina]

Hello Charles ,

Please find attached an example.

If you have further questions please do not hesitate to ask us.
I hope this will help you.

Sincerely yours,
Dimitrina
the Telerik team